Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm Rients Niks, Ursula Walther, Heidi Jaiser, Fernando Martinez, Diego Rubiales To cite this version: Rients Niks, Ursula Walther, Heidi Jaiser, Fernando Martinez, Diego Rubiales. Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm. Agronomie, EDP Sciences, 2000, 20 (7), pp.769-782. 10.1051/agro:2000174. hal-00886084 HAL Id: hal-00886084 https://hal.archives-ouvertes.fr/hal-00886084 Submitted on 1 Jan 2000 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Agronomie 20 (2000) 769–782 769 © INRA, EDP Sciences 2000 Original article Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm Rients E. NIKSa*, Ursula WALTHERb, Heidi JAISERc, Fernando MARTÍNEZd, Diego RUBIALESd, Ole ANDERSEN**, Kerstin FLATH**, Paul GYMER**, Fritz HEINRICHS**, Rickard JONSSON**, Lissy KUNTZE**, Morten RASMUSSEN**, Edeltraut RICHTER** a Laboratorium voor Plantenveredeling, Wageningen University, Postbus 386, 6700 AJ Wageningen, The Netherlands b Bundesanstalt für Züchtungsforschung an Kulturpflanzen, Theodor Roemer-Weg 4, 4320 Aschersleben, Germany c Pajbjergfonden, Gersdorffslundvej 1, Hou, 8300 Odder, Denmark d Instituto Agricultura Sostenible, CSIC, Apdo 4084, 14080 Córdoba, Spain (Received 28 April 2000; revised 9 July 2000; accepted 15 August 2000) Abstract – The level and type of resistance against leaf rust (Puccinia hordei) was determined in modern spring barley germplasm. In field trials all over Europe most accessions were in some locations and years significantly less infected than the moderately resistant reference ‘Grit’. Differentiating P. hordei isolates indicated that most accessions carried hypersensitivity (Rph) genes. A virulence survey indicated that among the known resistance genes, only Rph7 is still fully effective in Europe. Some accessions carried undetermined hypersensitivity resistance gene(s) that were effective to all isolates tested. The level of non-hypersensitivity or partial resistance was assessed from the latency period of the fungus and the percentage of early aborted infection units not associated with plant cell necrosis. These parameters indi- cated that several accessions had a level of partial resistance higher than that of the highly partially resistant ‘Vada’. We concluded that barley breeders have achieved very high levels of partial resistance against P. hordei in spring barley germplasm. barley / leaf rust / partial resistance / virulence / hypersensitivity Résumé – Résistance à la rouille brune (Puccinia hordei) du germplasme d’orge de printemps d’Europe de l’ouest. Le niveau et le type de résistance contre la rouille brune (Puccinia hordei) ont été déterminé chez le germplas- me d’orge de printemps. Dans des champs expérimentaux présents dans l’Europe entière, la plupart des accessions ont été pour certains sites et années, moins infectées comparé à la référence ‘Grit’ qui est modérément résistante. Des iso- lats de P. hordei différenciés ont indiqué que la plupart des accessions contenaient les gènes d’hypersensitivité Rph. Un test de virulence a indiqué que des gènes Rph connus, seul Rph7 est encore complètement efficace en Europe. Certaines Communicated by Hanne Østergård (Roskilde, Denmark) * Correspondence and reprints [email protected] ** Affiliations are in Appendix Plant Genetics and Breeding 770 R.E. Niks et al. accessions contenaient des gènes d’hypersensitivité indéterminés qui se sont avérés efficaces contre tous les isolats tes- tés. Le niveau de non-hypersensitivité ou résistance partielle a été évalué en fonction de la période latente du champi- gnon et du pourcentage des parties infectées après avortement hâtif non associés à la nécrose des cellules végétales. Ces paramètres ont indiqué que plusieurs accessions présentent un niveau de résistance partielle plus élevé que celui de la référence avec résistance partielle, ‘Vada’. Nous pouvons donc conclure que les sélectionneurs d’orge ont atteint des très hauts niveaux de résistance partielle contre P. hordei chez le germplasme de l’orge de printemps. orge / rouille brune / résistance partielle / virulence / hypersensitivité 1. Introduction pathogen. Such Rph genes confer incomplete resis- tance, in which the fungus forms small uredinia that are surrounded by chlorotic or necrotic plant Barley leaf rust, caused by Puccinia hordei Otth, tissue (i.e. low to intermediate infection types). occurs wherever barley (Hordeum vulgare L.) is The non-hypersensitivity resistance, also called cultivated. The economic importance of the rust “partial resistance” [18], is not associated with depends on the region in the world, and varies plant cell necrosis. It has a typically quantitative from year to year. In Europe, the disease is gener- inheritance [13, 20]. In field trials this resistance is ally more important in the temperate and warmer characterised by low levels of infection despite a regions, like the United Kingdom and France, and compatible (high) type of infection. In monocyclic less so in the more northern parts of Europe. In tests in the greenhouse, partially resistant barley 1998 and 1999, for example, leaf rust was among genotypes are identified by the long latency period the most important barley pathogens in the UK of the fungus and the low infection density as com- (Clarkson, NIAB, Cambridge, UK, pers. comm.). pared to the susceptible reference cultivars [15]. Losses of about 10 to 25% have been cited for the Czech Republic [3]. It appears that the economic Breeding for resistance to leaf rust in barley has importance of barley leaf rust has increased in not received top priority in European barley pro- recent years [2, 4]. grammes. However, selection against very suscep- tible phenotypes occurs. In several barley breeding In Europe, farmers apply repeated fungicide programmes, artificial inoculations are made on treatments on barley to protect against fungal leaf breeding lines to facilitate this selection. Such pro- pathogens, including barley leaf rust. There is cedures might result in the gradual accumulation of increasing opposition to the application of pesti- quantitative genes for resistance [14, 17]. cides in agriculture, because of the environmental and health risks. Here we describe the resistance of a set of mod- ern West-European spring barley germplasm The most obvious alternative to fungicide treat- against P. hordei. The accessions were tested at ment is the use of resistant cultivars. Resistance in several locations with the objective of assessing barley to P. hordei is widely available. There are the level and the type of their resistance. This two types of resistance to this pathogen: hypersen- research was complemented by a virulence survey sitivity resistance and non-hypersensitivity resis- to determine which Rph genes are still effective to tance [1]. The hypersensitivity resistance is gov- the pathogen in Europe, and the frequency of pos- erned by major genes (Rph), that are race-specific sible virulence factors in the P. hordei population. [5]. This resistance is often complete, and associat- Histological and macroscopic observations were ed with necrosis of plant cells that are attacked by carried out in a monocyclic greenhouse test to the pathogen sporelings. Some of the Rph genes determine the level of non-hypersensitivity resis- have a delayed or rather weak effect on the tance in the tested lines. Resistance to leaf rust in spring barley 771 2. Materials and methods alternating with them as microplots. At some loca- tions, the leaf rust epidemics were initiated by arti- ficial inoculation of the spreader rows, whereas in 2.1. Multi-location field test for resistance other locations, the epidemic occurred sponta- neously. 2.1.1. Plant material, locations and experimental design 2.1.2. Evaluation of infection levels Twenty-nine cultivars and breeding lines of spring barley were obtained from seven breeding Where possible, the trials were evaluated three companies or research institutes in Germany, times during the growing season starting at the Denmark and the Netherlands. Almost all those tillering stage (growth stages 21–23, [31]). The accessions were cultivars that had been released assessed parameter was the average percentage of since 1990, or breeding lines just about to be leaf area covered by the rust uredinia. A disease released. They had displayed consistently low lev- severity scale was provided to the evaluators at els of leaf rust infection in the breeders’ field trials, each location in order to reduce bias between loca- and hence were presumed to be partially resistant. tions and evaluators. ‘Alexis’ was added as a susceptible reference Data analysis was performed with the SAS- (three times), and ‘Grit’ as a moderately resistant application RESI [7]. The mean disease severity reference (four times). ‘Grit’ was used as refer- per accession per location per year was calculated ence, since it had shown a moderate and stable as